If an altimeter setting is not available before flight, to which altitude should the pilot adjust the altimeter?

• A. The elevation of the departure area
• B. The elevation of the destination area
• C. Sea level altitude
• D. The standard sea-level pressure

Answer: (A)

When you don’t have an altimeter setting available before flight, you set the altimeter to the elevation of the departure airfield. This provides a reliable reference point for your initial altitude relative to the ground at the point of departure, helping you maintain safe obstacle clearance as you start the flight. Once you can obtain the actual local setting, update the altimeter so it reflects the true altitude above mean sea level. Using the destination’s elevation or any sea-level/standard pressure alone would misrepresent your true height early in the flight, since they don’t account for the local air pressure at the departure area.